International travel, the gut microbiome, and ESBL-E coli carriage
Authors: Ye Peng, Daniel Zhen Ye Sin, Hein M Tun
Journal: The Lancet Microbe (2022)

We read with interest the Article by Quinten R Ducarmon and colleagues1Ducarmon QR Zwittink RD Willems RPJ et al.Gut colonisation by extended-spectrum β-lactamase-producing Escherichia coli and its association with the gut microbiome and metabolome in Dutch adults: a matched case-control study.Lancet Microbe. 2022; 3: e443-e451Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar in The Lancet Microbe reporting the absence of association of asymptomatic carriage of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli with microbiome composition and functions. Although their analyses were comprehensive and added knowledge to the literature, we would like to discuss the potential influence of participants' past travel history on the study's original observation. International travel has an effect on gut microbiota,2Kampmann C Dicksved J Engstrand L Rautelin H Changes to human faecal microbiota after international travel.Travel Med Infect Dis. 2021; 44102199Crossref PubMed Scopus (2) Google Scholar and has been considered a risk factor for the acquisition of ESBL-producing Enterobacteriaceae.3Furuya-Kanamori L Stone J Yakob L et al.Risk factors for acquisition of multidrug-resistant Enterobacterales among international travellers: a synthesis of cumulative evidence.J Travel Med. 2020; 27taz083Crossref Scopus (20) Google Scholar, 4Peng Y Liang S Poonsuk K et al.Role of gut microbiota in travel-related acquisition of extended spectrum β-lactamase-producing Enterobacteriaceae.J Travel Med. 2021; 28taab022Crossref Scopus (9) Google Scholar However, in Ducarmon and colleagues' study,1Ducarmon QR Zwittink RD Willems RPJ et al.Gut colonisation by extended-spectrum β-lactamase-producing Escherichia coli and its association with the gut microbiome and metabolome in Dutch adults: a matched case-control study.Lancet Microbe. 2022; 3: e443-e451Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar no significant correlation was observed between international travel history in the past 6 months and the carriage of ESBL-producing E coli. When we re-visited the published data, within the stratum of no recent international travel, we observed significant gut microbiota differences between ESBL-producing E coli positive carriers and non-carriers, mainly driven by Bifidobacterium adolescentis and several Firmicutes bacteria (appendix p 1). Specifically, ESBL-producing E coli carriers had a reduced abundance of B adolescentis and an increased abundance of Firmicutes phylum. These findings were undetectable without considering travel history. Previously, we reported a decreased Actinobacteria species richness both before and after travel among individuals who acquired ESBL-producing Enterobacteriaceae during travel.4Peng Y Liang S Poonsuk K et al.Role of gut microbiota in travel-related acquisition of extended spectrum β-lactamase-producing Enterobacteriaceae.J Travel Med. 2021; 28taab022Crossref Scopus (9) Google Scholar Actinobacteria in the human gut mainly comprises bifidobacteria, especially B adolescentis in adults. B adolescentis has been shown to be depleted in individuals with ESBL-producing Enterobacteriaceae from a French cohort, and was hypothesised to inhibit ESBL-producing Enterobacteriaceae via short-chain fatty acid production.5Le Bastard Q Chapelet G Birgand G et al.Gut microbiome signatures of nursing home residents carrying Enterobacteria producing extended-spectrum β-lactamases.Antimicrob Resist Infect Control. 2020; 9: 107Crossref PubMed Scopus (6) Google Scholar Thus, B adolescentis, as the most abundant species in the Ducarmon and colleagues' cohort,1Ducarmon QR Zwittink RD Willems RPJ et al.Gut colonisation by extended-spectrum β-lactamase-producing Escherichia coli and its association with the gut microbiome and metabolome in Dutch adults: a matched case-control study.Lancet Microbe. 2022; 3: e443-e451Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar might confer colonisation resistance against ESBL-producing E coli when there is no other microbiota-influencing factor such as travel history. However, the effect of international travel on this gut species warrants longitudinal studies. Additionally, because of the immune modulatory role of B adolescentis and short-chain fatty acids, further evidence on host–microbe interactions, including host immune facilitators, could reveal a new mechanistic insights on the colonisation resistance of ESBL-producing E coli. Moreover, although we acknowledge the justification on a single ESBL-producing species (E coli) rather than a broad group, without information on the colonisation of other ESBL-producing species and their potential for horizontal gene transfer, we are uncertain if the results of this study support the hypothesis that colonisation resistance of ESBL-containing E coli is not as relevant as other enteric pathogens in the same cohort. We declare no competing interests. All authors are supported by the Health and Medical Research Fund Fellowship Scheme (04180077) of the Hong Kong Special Administrative Region, China. Download .pdf (.31 MB) Help with pdf files Supplementary appendix Gut colonisation by extended-spectrum β-lactamase-producing Escherichia coli and its association with the gut microbiome and metabolome in Dutch adults: a matched case-control studyBy combining multiomics and machine-learning approaches, we conclude that asymptomatic gut carriage of ESBL-producing E coli is not associated with an altered microbiome composition or function. This finding might suggest that microbiome-mediated colonisation resistance against ESBL-producing E coli is not as relevant as it is against other enteropathogens and antibiotic-resistant bacteria. Full-Text PDF Open AccessInternational travel, the gut microbiome, and ESBL-E coli carriage – Authors' replyWe thank Ye Peng and colleagues for their reaction to our Article1 and for re-analysing part of our data. As strong advocates of open science, we are glad that other researchers re-use our data, which were made available fully open access and findable, accessible, interoperable, and reusable (FAIR) for this purpose. Full-Text PDF Open Access